Abstract
Muon spin relaxation resulting from spin exchange scattering of endohedral muonium () with thermal electronic excitations has been observed in the fullerene superconductor . The temperature dependence of shows a coherence peak just below and can be fit to the conventional Hebel-Slichter theory for spin relaxation in a superconductor with a broadened BCS density of states. The average energy gap for electronic excitations, Δ/=53(4) K or 2Δ/=3.6(3), is consistent with the BCS weak coupling limit.
- Received 21 April 1993
DOI:https://doi.org/10.1103/PhysRevLett.70.3987
©1993 American Physical Society